... , Gas detector.Semiconductor sensor for Flammable gas, Plastic or Metal coverModelTarget GasApplication CircuitConfigurationDatasheetMQ-2General combustible gas MQ-3Alcohol MQ-4Natural gas, Methane MQ-5LPG, Natural gas, Coal gas ... MQ-6LPG, Propane MQ-7 Carbon Monoxide MQ-8Hydrogen MQ-9CO and Combustible gas MQ306LPG ...